package com.codeforces;

import java.util.Scanner;

public class _59A {

	static String s;
	static Scanner scanner = new Scanner(System.in);
	static int up, down;

	public static void main(String[] args) {
		s = scanner.next();
		up = down = 0;
		for (int i=0;i<s.length();++i) {
			char ch = s.charAt(i);
			if (ch >= 'a' && ch <= 'z') {
				down++;
			}
			else {
				up++;
			}
		}
		if (up > down) {
			for (int i=0;i<s.length();++i) {
				char ch = s.charAt(i);
				if (ch >= 'a' && ch <= 'z') {
					ch = (char) (ch - 'a' + 'A');
				}
				System.out.print(ch);
			}
		}
		else {
			for (int i=0;i<s.length();++i) {
				char ch = s.charAt(i);
				if (ch >= 'A' && ch <= 'Z') {
					ch = (char) (ch - 'A' + 'a');
				}
				System.out.print(ch);
			}
		}
	}

}
